what can i do with 5mm glass??

[Reef Puffer]

is there a shape (ie: hex,pentagon,rectangle,square...) that might me structurally more stable?

[Nano]

Hex probably with thin glass would be ok. But personally that's pqrette thin glass.

[Reef Puffer]

ya i think its thin too. i built my sump with no issues and that calculator says i can go quite large? i searched 5mm glass here on canreef and this guy had a 60 gal over 20 inches high that was professionally built will 5mm glass as far as i could tell?

[bignose]

I wouldn't go bigger than 20G it's too risky. I would be constantly be worried about the pressure, my tank is 18" tall and has glass twice as thick.